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Abstract:

Sensors mounted on a textile include at least one of electrically
conductive textile electrodes; single or multiple optically coupled
infrared and red emitter and photodiode or photo transistor; and thin
film or Resistive Temperature Detector (RTD). Textile electrodes,
electrical connections, and electrical functionalization use at least one
of nanoparticles, nanostructures, and mesostructures. Conductive thread,
for electrical connections, may include a fiber core made from conductive
materials such as but not limited to metals, alloys, and graphine
structures, and a sheath of insulating materials such as but not limited
to nylon, polyester, and cotton.

Claims:

1. Sensors mounted on a textile, comprising at least one of: a.
electrically conductive textile electrodes; b. single or multiple
optically coupled infrared and red emitter and photodiode or photo
transistor; and c. thin film or Resistive Temperature Detector (RTD).

2. Textile electrodes, electrical connections, and electrical
functionalization using at least one of nanoparticles, nanostructures,
and mesostructures.

3. A device according to claim 2, wherein the nanoparticles,
nanostructures and mesostructures comprise ink suspensions in organic
binders.

4. A device according to claim 3, wherein the ink suspensions in organic
binders include acrylic, epoxy, heat curable, and photo curable resins.

5. A device according to claim 3, wherein the ink suspensions are
compatible with textile compatible pattern transfer techniques.

6. A device according to claim 5, wherein the patter transfer techniques
include screen printing, stamping, ink jet, and gravure.

7. A device according to claim 2, wherein the nanoparticles,
nanostructures and mesostructures are deposited on textile.

8. A device according to claim 2, wherein the nanoparticles,
nanostructures and mesostructures are deposited on textile by at least
one of flocking and dyeing.

9. A device according to claim 1, wherein the sensors include said
textile electrodes for sensor-actuator applications.

11. A device according to claim 1, wherein the sensors are mounted on an
arm band, for monitoring pulsatile blood flow in major arteries of the
body.

12. A device according to claim 11, wherein the position of the sensors
can be adjusted based on the diameter of wearer's arm.

13. A device according to claim 1, wherein the sensors are configured to
monitor thermal distribution in a person's body.

14. A device according to claim 2, wherein said electrical connections
comprise conductive thread, said conductive thread comprising: a fiber
core made from at least one conductive material; and a sheath made from
at least one insulating material.

15. The device of claim 14, wherein the conductive material comprises at
least one of metals, alloys, and graphine structures, and the insulating
material comprises at least one of nylon, polyester, and cotton

16. A device according to claim 5, wherein electrical connections,
resistant to triboelectric effect, for sensor signal relay are printed
with said ink suspensions.

17. A device according to claim 10, wherein electrical connections,
resistant to triboelectric effect, for sensor signal relay are made of
said conductive threads.

18. A device according to claim 2, further comprising an electrical
connector assembly for connecting said electrical connections to an
electronics module.

19. A device according to claim 10, further comprising an electrical
connector assembly for connecting said conductive thread connections to
an electronics module.

20. A textile comprising: at least one sensor enmeshed in the textile,
the sensor comprising a textile-based or textile-integrable sensor; at
least one textile-based or textile-integrable amplifier-transmission
module configured to be electrically coupled with the sensors; and a
textile-based or textile-integrable power supply configured to be
electrically couple with at least one of the sensor and the
amplifier-transmission module.

21. The textile of claim 20, wherein the textile comprises a garment
configured to be worn by a user.

22. The textile of claim 21, wherein the textile houses one of: a.
connective lines of conductive fiber with a metallic or alloy core for
supporting at least one of electrical, optical, opto-electronic, and
electro-mechanical medical monitoring devices on or in the vicinity of
the user wearing the garment; b. connective lines of conductive fiber
with metallic or non-metallic conductive nanoparticles blended or
decorated fabric for supporting at least one of electrical, optical,
opto-electronic, and electro-mechanical medical monitoring devices on or
in the vicinity of the user wearing the garment; c. connective lines of
conductive filament with a metal coated fiber or alloy-fiber blend core
for supporting at least one of electrical, optical, opto-electronic, and
electro-mechanical medical monitoring devices on or in the vicinity of
the user wearing the garment; and d. connective lines of optic fiber for
supporting at least one of electrical, optical, opto-electronic, and
electro-mechanical medical monitoring devices on or in the vicinity of
the user wearing the garment.

23. The textile of claim 22, wherein the garment is washable.

24. The textile of claim 20, further comprising a system for
communicating signals from said at least one sensor to a computational
device for data logging and post-processing.

25. The textile of claim 20, wherein the system is configured to
communicate with at least one of a smart phone and a wireless
communication device, wherein at least one of said smart phone and said
wireless communication device is an interface for data acquisition and
storage, display, and simultaneous relay of data to a cyber
infrastructure based cloud computing network for data post processing and
storage.

26. The textile of claim 20, wherein said at least one sensor comprises
at one of: a fabric-based or film-based resistive or capacitive
electrode, with hierarchically organized nanostructures, for Biopotential
sensing; a plethysmographic optical-reflectance, absorbance and
transmittance-array for blood flow monitoring; a piezoelectric fabric or
film based hydrophone sensor enmeshed in the textile for proximal broad
spectrum acoustic monitoring for medical diagnostics; a piezo-resistive
fabric or film based strain sensitive sensor enmeshed in the textile for
thoracic distention; and a fabric or film based resistive temperature
detector for spatio-temporal body temperature profiling.

Description:

CROSS-REFERENCE TO RELATED APPLICATION

[0001] This application claims the benefit of priority under 35
U.S.C.§119(e) of U.S. Provisional Patent Application No. 61/450,423,
filed Mar. 8, 2011, the disclosure of which is incorporated herein by
reference.

TECHNICAL FIELD

[0002] The present disclosure relates to electronic and optical sensor
technologies, and their packing to enable their integration into textile.
These sensor capabilities will enable the use of textile for health
monitoring, while operating in contact or in proximity of person's body.

BACKGROUND

[0003] Chronic disease management and in-hospital patient care are two
major contributors to healthcare costs. The former consists of patients
in need of repeated tests to assess disease progression or protocols for
drug dosage adjustments. The latter consists of patients recovering from
surgeries or in need for constant observation for diagnosis. They
contribute to approximately 30% ($690 billion) and 20% ($460 billion) of
the annual healthcare costs, respectively, in the United States of
America. See, e.g., Tabibiazar R., Edelman S. V., "Silent Ischemia in
People With Diabetes: A Condition That Must Be Heard," Clinical Diabetes,
Vol. 21 (1), 5-9 (2003), the disclosure of which is incorporated herein
by reference.

[0004] Cardiovascular diseases and neurological disorders form the
majority of diseases that need constant or periodic medical attention.
The concept of continuous health monitoring can be translated as point of
care technology for preventive/corrective medicine and as metabolic rate
estimation and regulation as a part of healthy lifestyle. Point of care
technology aims at enabling diagnostics in hospice, at home or ambulatory
(on the move).

[0005] Health monitoring textile is a type of wearable and ambient
healthcare technology: an ensemble of non-invasive sensor systems, which
operates in contact or in proximity of person's body. Resemblance to a
conventional wearable item (apparel) or integrability in it increases the
relevance of such a device. Wearable fabric based items like vests,
socks, shorts, head bands, arm bands, wrist bands and caps, foot wear,
and drapes like bed spreads/sheet and pillow covers can incorporate
sensors for monitoring the health of an individual for diabetes,
neurological, and cardiovascular monitoring.

[0006] Neurological disorders such as sleep disorders and sleep
deprivation affect more than thirty million people, while another six
million have moderate to severe sleep apnea in which breathing briefly
stops. That is nearly one in five Americans, making sleep apnea as
prevalent as asthma or diabetes. More than six million people have
restless leg syndrome and periodic limb movement disorder which jolts
them awake repeatedly. As many as twenty-five million people remain
undiagnosed and untreated which will account for over $22 billion in
unnecessary health care costs. Apart from physical factors such as
obesity, studies have shown that the cumulative long-term effects of
sleep loss and sleep disorders are associated with a wide range of
serious health consequences and many life threatening illnesses including
increased risk of hypertension, diabetes, depression, heart attack,
impotence and stroke, to name a few. In addition, a significant
percentage of severe traffic and industrial accidents may be caused by
the involuntary human transition from wakefulness to sleep.

[0007] There are also apparent links between deficits in brain chemistry
and obstructive sleep apnea (OSA) and REM sleep behavior disorder (RBD).
Both are relatively common sleep problems that disturb the slumber and
daytime behavior of millions of Americans. It has been reported that
multiple system atrophy (MSA), a rare and fatal degenerative neurological
disease, is almost always accompanied by severe sleep disorder. Patients
with the fewest dopamine-producing neurons in the striatum of their
brains had the worst RBD symptoms, talking and violent flailing during
their sleep. People with OSA show tissue loss in brain regions that help
store memory, thus linking OSA with memory loss and Alzheimer's disease.
Obstructive sleep apnea, in which breathing temporarily stops during a
person's sleep, often affects adults but goes undiagnosed in many cases.
Its most notable symptoms are snoring and excessive daytime sleepiness,
though it can also affect blood pressure, memory and even reaction-time
while driving.

[0008] What is needed is a robust and non-disruptive monitoring bed
sheets- and pillow cases-based system that addresses continuous
biopotential measurements, which can analyze and record the required
parameters while the patient is at home and sleeping in his or her own
bed.

[0009] Textiles offer a durable platform for embedded sensor and
communication systems, with the components like sensors and communication
chip-sets stitched or woven into the fabric. Individual electronic
components can be mounted on the textile and connected through electrical
connects that have been built in or manufactured in the textile itself.
The electronic functionality should be embedded while maintaining the
textile properties of product like wearing comfort and durability.
Manufacturing techniques used for such smart textiles have to be
compatible with existing textile manufacturing techniques to minimize
additional costs.

[0010] Physiological signals, such as but not limited to,
Electrocardiogram (ECG), Pulse rate (and heart rate variability), blood
pressure, Electroencephalography (EEG), electro-oculography (EOG) and
electromyography (EMG), provide a comprehensive medical status of a
person. In combination with wireless communication technology, they can
be used for remote medical diagnosis or prognosis. Textile based dry
electrodes with lower electrode-skin contact impedance for improved
performance in bioelectric signal acquisition is important to achieve
un-obstructive and long term health monitoring. This is not possible with
conventional wet electrodes due to drying of the conductive gel over
period of time that leads to loss of functionality and skin irritation.
Un-obstructive blood pressure monitoring requires an alternative to the
conventional inflatable cuff based sphygmomanometer. Also, such a setup
is difficult to incorporate in textile and very energy intensive for
mobile health monitoring.

[0011] Printing processes can be used for making complex high resolution
designs on a wide range of substrate, including textile. See, e.g.,
Sherman, R., "Could Printed Electronics Replace Traditional Electronics?"
Printed Circuit Design & Fab, 27 (3), 38, 40, 42 (2010), the disclosure
of which is incorporated herein by reference. Printing allows for direct
pattern transfer of electronics with little or no waste of material and
thus a cost effective alternative to photolithography techniques. Among
the popular printing technologies, screen printing and gravure are well
suited for mass produced electronics on textile because of their parallel
printing technology and the substrate handling. See, e.g., Sheats, J.,
R., Biesty, D., Noel, J., Taylor, G., N., "Printing technology for
ubiquitous electronics," Circuit World, 36 (2), 40-47 (2010); Kah, B.,
E., "Printing methods for printed electronics," 24th International
Conference on Digital Printing Technologies. Digital Fabrication 2008,
15-20 (2008), the disclosures of which are incorporated herein by
reference.

[0012] Parallel printing, as compared to serial printing technologies like
ink jet printing, has a higher manufacturing throughput. Screen printing
and gravure printing technologies do not deviate significantly from
garment making techniques making them cost effective. These technologies
will enable fabrication (over a large surface area) of electronics with
varied functionality like:--sensor systems and flexible printed circuits
for electrical connections between sensors and the embedded wireless
telemetry systems.

[0013] The textile based healthcare applications and packaging technology
described in this section aim at improved sensor performance and seamless
integration of the sensor systems in the textile for un-obstructive
health monitoring. The technologies use a novel combination of
nanomaterials and textile fabric for sensor and packaging electronics.

SUMMARY

[0014] According to various aspects of the disclosure, sensors mounted on
a textile include at least one of electrically conductive textile
electrodes; single or multiple optically coupled infrared and red emitter
and photodiode or photo transistor; and thin film or Resistive
Temperature Detector (RTD).

[0015] According to the disclosure, textile electrodes, electrical
connections, and electrical functionalization use at least one of
nanoparticles, nanostructures, and mesostructures.

[0016] In accordance with some aspects of the disclosure, conductive
thread, for electrical connections, may include a fiber core made from
conductive materials such as but not limited to metals, alloys, and
graphine structures, and a sheath of insulating materials such as but not
limited to nylon, polyester, and cotton.

[0017] Further advantages and embodiments are apparent from the appended
drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

[0018] In the figures:

[0019] FIG. 1 illustrates a design of an exemplary arm band for brachial
artery plethysomography in accordance with various aspects of the
disclosure;

[0020] FIG. 2 illustrates an exemplary mechanism for adjusting the
relative positions of the sensors according to various aspects of the
disclosure;

[0021] FIG. 3 illustrates an exemplary packaging technology for the
sensors in accordance with various aspects of the disclosure;

[0022] FIG. 4 is a graph showing the signal from an exemplary 3-Lead ECG
dry textile electrodes system with leads 1, 2, and 3 plotted
simultaneously;

[0023] FIG. 5 is a graph of a leading electrocardiograph (lead 2) and
lagging brachial artery pulse data acquired on the same time line for
measurement of pulse transit time;

[0027] Theta and Delta waves from a textile sensor in pillow cases and bed
sheets.

DETAILED DESCRIPTION

[0028] The electrode design for electrophysiological sensing (ECG, EEG,
etc.) is developed as a electrically functionalized piece of fabric
mounted on a spring mechanism. The electrode fabric is dyed with
conductive ink, or enmeshed/decorated with conductive nanoparticles. The
electrode surfaces have been engineered to have nanoscale and mesoscale
free standing conductive structures. This is done to increase the
effective surface area of the electrodes. Electrode surface area, which
is in contact with the skin, is important to the signal quality. The
signal measured is electric potential across the load resistance between
the two electrodes that can be conceived as the impedance due to body
bulk, skin and electrodes. Large electrode surface area results in low
skin-electrode contact resistance. The free standing structures are
deposited on the above mentioned conductive fabric by flocking
electrically conductive fibers. Another technique is printing the
electrodes with nanocomposite ink, which will have nanostructures on the
surface of the printed thick film for increase surface area. Printed
electrode for Electrocardiography (ECG, EEG etc.) is a technology based
on the fabric itself. The electrodes system printed on the textile serves
for multi-lead ECG signal acquisition, when the electrode surface is in
contact with person's skin. The composition of the ink will be described
in more detail below.

[0029] FIG. 1 illustrates the design of an arm band for brachial artery
plethysomography. The optically coupled infrared emitters and photodiode
have been arranged in arrays and connected to a breakout plug that can be
connected to the primary circuit on the textile. Blood pressure
measurement system is an opto-electronic system, plethysmograph (PPG)
that monitors the blood flow in the brachial artery in the left arm. A
multichannel infra red emitter-detector (FIG. 1) system is placed on the
left on the axis of the brachial artery (inside part of the left arm) to
detect change in blood flow of the brachial artery. The system is used in
combination with the ECG measurement to estimate the time it takes for
the pulse, pulse transit time (PTT) to move from the aortic valve to the
PPG site. The PTT is an index for estimation of arterial blood pressure
(ABP). The PPG system uses infrared reflectance by the blood for
monitoring the blood flow volume. Positions for the emitter arrays 1 and
the detector array 2 are important to get the optimum reflectance
signature.

[0030] FIG. 2 illustrates the mechanism for adjusting the relative
positions of the sensors. The sensors positions can be changed by sliding
the emitter arrays on a spin and securing them by hock and loop to
accommodate for different arm diameters. The size of the arm varies from
person to person. To address this issue, provision for adjusting the
array spacing has been provided. The emitters and detectors are surface
mounted devices (SMDs). (FIG. 2) They have been soldered on to a flexible
printed circuit 3, 10 with flat flexible connections running between
components. This is to enable packaging of the components in a textile
based arm band. The components are arranged in three arrays. Array in the
middle is stationary, while the flanking arrays can move on two spines 4.
The system uses hook and loop arrangement 5, 11 to secure the arrays in
position. The band system has been designed as a detachable component of
the textile health monitoring system. A flat flexible connection port 6
is provided on the band for connection to ancilliary or master circuit
for power supply and signal relay. The use of flexible printed circuit is
to enable packaging of the components in a textile based arm band 7 with
a buckle 8, and hock and loop 9 for strapping around the arm.

[0031] FIG. 3 illustrates the packaging technology for the sensors. The
textile based electric connection lines for the sensors are linked to the
break out pins of a socket. The figure depicts the socket with thread as
well as printed lines on fabric. The corresponding plug is mounted on the
electronics for wireless communication and power supply. Similar concept
is used for connecting the arm band electronics to the master circuit.
Printed electrical connects, on the textile fabric, can function like a
flexible textile based printed circuit film. This will act as a system to
facilitate packaging of the sensor systems, and amplifier-transmitter
electronics in the textile. (FIG. 3) The connect lines or conductive
traces 12 use nanomaterial composite based inks. The binder itself can
serve as printing ink, so that the conductive traces can be insulated by
an overlay of traces made with binder only. The ink formulation uses
modified acrylic, epoxy or resin binders with conductive nano particles
and nanostructures dispersed in it. The nanocomposite based conductive
patterns provide electrical properties similar to conductive metal wires
or strips, while being able conform with the flexibility of textile.
Binder's adhesion properties allow for printing on nylon, cotton, lycra,
spandex, neoprene or other elastomeric fabric or film. The binder
possesses high elasticity; therefore, it will protect the traces from
disruption due to stretching of the fabric or film.

[0032] Textile based connections for packaging of sensor and wireless
electronics in textiles, can be accomplished with conductive threads 13.
The textile health monitoring system also uses conductive threads made of
conductive fiber core and an insulation sheath. Conductive fiber core can
be made of metals like silver, copper, titanium; alloys like stainless
steel, nickel-cromium; and graphine structures like carbon nanotubes. The
sheath can be made of nylon, polyester, and cotton. These threads are
compatible with machine weaving. In addition to being compatible with
textile platform, the printed connections and conductive threads are
resistant to triboelectric effect. This prevents build up of static
charge, which occurs when wearing textile products. Thus, signal
artifacts due to static charge build up are avoided.

[0033] The printed connections and conductive thread connections are
required to be able to connect to the electronics for wireless
communication and power supply. While these components are not made on
textile substrate, their electronic connects do not readily interface
with the textile based connects. The textile health monitoring system
uses a special electronic connector assembly (FIG. 3), which houses a
socket 14 with break out pins attached to corresponding textile connects
15 with rivets, crimps or silver epoxy. The socket is compatible to the
plug 16 on the electronic module for wireless communication and power
supply.

Wireless Communication Platform:

[0034] Coupled with a low power microcontroller and Bluetooth module
(Zigbee, WiFi and other communication protocols as appropriate), the
sensor data can be streamed to commercial off-the-shelf cell phones and
smart phones, laptops, computer, and handhelds units. A software system
has also been developed for cellular `smartphones` that can collect
sensor data over Bluetooth and can relay data over 3G, Wi-Fi, WiMax or
any outgoing connection with RFID. Apart from the cost benefits of using
an off-the-shelf cell phone for data relaying, our software system will
provide two other distinguishing features. First, it will implement
filtering algorithms on the cell phone to mitigate issues due to motion
and other artifacts, rendering clean data. It will provide a
visualization interface at the cell phone through which users can see
salient features of their heart activity such as heart rate. The software
on the phone will run simple machine learning algorithms to perform
preliminary anomaly detection. In case of an emergency, it can either
alert the user and recommend him/her to hospital locations near his/her
present location or make an automated call to the patient's physician
with his/her present location. Thus caregivers can access into vital
information anywhere and at anytime within the healthcare networks. The
Zigbee based WiFi system used is capable of handling 65,000 patients at a
given time.

[0035] The geo-tagged data is transferred to a cloud cluster and stored in
a secure database and SD card. For physician diagnostics we will provide
a new backend service, where the doctor can log into our system and can
visually look at past ECG, EEG and other related data from the user or
real-time continuous data (whichever is deemed necessary). If the
physician desires, he/she can use our machine learning services to detect
anomalies in the data that was collected in the past. In the event that
our machine learning algorithms detect abnormalities in the data, our
VoIP service can make phone calls or send SMS messages to physicians.

[0036] The example presented in FIG. 4 is to illustrate the ability of the
smart textile health monitoring system to acquire 3 lead ECG signal using
dry textile electrodes. ECG acquired here are Lead 1- between augmented
right arm and augmented left arm, Lead 2- between augmented right arm and
augmented left leg, and Lead 3- between augmented left leg and augmented
left arm. This basic form of ECG acquisition monitors the atrial activity
and ventricular activity of the heart. The data is also used for heart
rate calculation and arterial blood pressure estimation.

[0037] The example presented in FIGS. 5 and 6 illustrates the blood
pressure estimation application. While FIG. 5 shows the concept behind
calculation of the pulse transit time (PTT), FIG. 6 shows the calibration
curves used as the transducer functions for estimation of atrial systolic
and diastolic blood pressure from PTT.

[0038] The example presented in FIG. 7 illustrates the body temperature
sensing application of the flexible thin film temperature sensor. The
calibration curve is used as a function by the signal acquisition
software for converting the change in resistance of the thin film channel
to temperature. The range of linear response is 32° C. to
38° C., which is the range of the temperatures observed at the
axilliary location of the arm. The axial temperature range that covers
from normal condition to feverish. See, e.g., Lodha, R., Mukerji, N.,
Sinha, N., Pandey, R., M., and Jain, Y., "Is Axillary Temperature an
Appropriate Surrogate for Core Temperature?" Indian Journal of
Pediatrics, 67 (8), 571-574 (2000), the disclosure of which is
incorporated herein by reference.

[0039] The examples presented in FIG. 8 are typical brain rhythm as
measured by the textile based sensor system. They are consistent with the
regular wet gel electrodes used in the hospital. See, e.g., Allan
Rechtschaffen and A. Kales, A manual of standardized terminology,
techniques and scoring system for sleep stages of human subjects, Brain
Information Service/Brain Research Institute, University of California,
Los Angeles, Calif. (1977), the disclosure of which is incorporated
herein by reference.

[0040] It will be apparent to those skilled in the art that various
modifications and variations can be made to the smart materials, dry
textile sensors, and electronics integration in clothing, bed sheets, and
pillow cases of the present disclosure without departing from the scope
of the invention. Throughout the disclosure, use of the terms "a," "an,"
and "the" may include one or more of the elements to which they refer.
Other embodiments of the invention will be apparent to those skilled in
the art from consideration of the specification and practice of the
invention disclosed herein. It is intended that the specification and
examples be considered as exemplary only.